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FIG 2. Same patient as in Figure 1. A, Mastercut view through the right VA with straightening of both extracranial and intracranial portions shows diffuse narrowing of the intracranial segment from the level of the foramen magnum. B, Mastercut through the left VA shows focal narrowing (arrow) at the intracranial segment C–E, Sections perpendicular to the arterial long axis below (C), at (D), and above (E) the focal spasm provide accurate measurements of vascular diameter at each location. Note the evenly narrowed diameter of the diffusely spastic right VA.
